RU2700290C2 - Vehicle equipped with shock-absorber - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: group of inventions relates to a vehicle equipped with a shock absorber. Vehicle comprises self-propelled vehicle body, in which front wheel and rear wheel are provided, mechanical damper with variable damping force and damper with adjustable damping force. Mechanical damper with variable damping force is located between vehicle body and front wheel and is configured to mechanically change damping force. Shock absorber with adjustable damping force is located between vehicle body and rear wheel and is configured to adjust damping force according to control signal from controller by means of actuator at vehicle turn.

EFFECT: possibility to adjust shock absorbers damping force.

32 cl, 8 dwg

Description

State of the art

[0001] The present invention relates to a vehicle equipped with a shock absorber, such as a four-wheeled vehicle including a shock absorber mounted, for example, on each side of the front wheels and the side of the rear wheels.

[0002] In general, on vehicles such as four-wheeled vehicles, a shock absorber is mounted on each wheel to enable vibration damping when the vehicle is moving. One type of shock absorber, in accordance with conventional technology, is a shock absorber that can mechanically vary the damping force. Known examples of it include a shock absorber sensitive to stroke length, configured to change the damping force characteristic in accordance with the position during the stroke of the piston rod (for example, see international publication No. 2013/081004). In addition, a shock absorber with an adjustable damping force is also known, including an electronically controlled actuator that alternately regulates the generated damping force in accordance with, for example, the conditions in which the vehicle is moving, which include the road surface condition (for example, see Japanese Patent Application Publication No. 2009-281584).

[0003] [Patent Literature 1]

International Publication No. 2013/081004

[Patent literature 2]

Japanese Patent Application Publication No. 2009-281584

[0004] The shock absorbers described above, sensitive to the stroke of the shock absorber, in accordance with international publication No. 2013/081004, are configured to change the damping force characteristics in accordance with, for example, the position of the piston rod stroke, and do not require a sensor, etc. ., for detecting, for example, the conditions in which the vehicle is moving. Such an exception leads to the advantages of eliminating the need to use an electronically controlled actuator, etc. and simplifying the entire configuration, which thus reduces production costs and improves convenience during assembly. However, a shock absorber configured to mechanically change the damping force, such as a shock-sensitive shock absorber, cannot variably adjust the generated damping force according to the conditions under which the vehicle moves when the road surface changes, etc., therefore, it does not necessarily sufficiently improve driving comfort, stability of maneuvering, etc. vehicle.

[0005] On the other hand, the shock absorber with adjustable damping force, in accordance with the publication of Japanese Patent Application No. 2009-281584, has a complicated function that can improve driving comfort and stability when maneuvering a vehicle. However, in this case, the shock absorber requires a sensor, etc. to detect the conditions in which the vehicle is moving, such as changes in the surface of the road, etc., and uses an expensive electronically controlled actuator and the like, resulting in a problem of complicating the entire configuration and not improving convenience during production and assembly.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to solve at least one of the problems described above.

To solve the above problem, in accordance with an aspect of the present invention, a mechanical shock absorber with a variable damping force, configured to change the damping force, and a shock absorber with an adjustable damping force are combined with each other.

[0007] In accordance with an aspect of the present invention, a vehicle equipped with a shock absorber includes a self-propelled vehicle body in which a front wheel and a rear wheel are provided, a mechanical shock absorber with a variable damping force located between the vehicle body and the front wheel and configured with the ability to mechanically change the damping force, and a shock absorber with an adjustable damping force located between the vehicle body and the rear to forest and configured to adjust the damping force using the actuator.

[0008] In accordance with an aspect of the present invention, a suspension system that is used in conjunction with a vehicle including a vehicle body, a front wheel and a rear wheel includes a mechanical damper with a variable damping force located between the vehicle body and the front wheel and made with the possibility of mechanical changes in the damping force, and a shock absorber with adjustable damping force, located between the vehicle body and the rear wood and made with the possibility of regulating the damping force using an actuator.

Brief Description of the Drawings

[0009] FIG. 1 is a perspective view showing a four-wheeled vehicle as a vehicle equipped with a shock absorber in accordance with an embodiment of the present invention.

In FIG. 2 is an enlarged vertical cross-sectional view illustrating a stroke-sensitive damper mounted on the front wheel side, as shown in FIG. one.

In FIG. 3 illustrates a configuration of a circuit in which a stroke-sensitive damper shown in FIG. 2.

In FIG. 4 illustrates characteristic lines, each of which represents the relationship between the position of the stroke and the damping force of the damper sensitive to the stroke.

In FIG. 5 is a control block diagram illustrating a damper with damping force control mounted on the rear wheel side, as shown in FIG. 1, together with a controller, etc.

In FIG. 6 shows characteristic lines, each of which represents characteristics of a rotation angle or an angle of inclination when a vehicle is being driven, when compared between a vehicle in accordance with the present embodiment and comparative examples.

In FIG. 7 is an enlarged view illustrating the main parts of the characteristic lines shown in FIG. 6.

In FIG. 8 illustrates characteristic lines, each of which represents a relationship between a roll angle and a pitch angle when a vehicle is controlled when comparing between a vehicle in accordance with the present embodiment and comparative examples.

Detailed Description of a Preferred Embodiment

[0010] In the following description, a suspension system and a vehicle equipped with a shock absorber in accordance with an embodiment of the present invention will be described. The present embodiment will be described in detail with reference to the attached drawings in FIG. 1-8, suggesting that a vehicle equipped with a shock absorber is embodied, by way of example, as a four-wheeled vehicle, commonly referred to as a small car.

The suspension system, in accordance with the present embodiment, includes a shock absorber 6, sensitive to the course of the rod, as a mechanical shock absorber with variable damping force, and a shock absorber 9 with control of the damping force, which will be described below.

[0011] As shown in FIG. 1, an engine (not shown), such as an internal combustion engine, is mounted in a vehicle body 1 constituting the main structure of a vehicle (subcompact) of a vehicle), and for example, a plurality of seats (not shown) including a driver's seat are provided in the back of 1 vehicle. For example, the front left and right wheels 2 (only one of them is shown), and the rear left and right wheels 3 (only one of them are shown) are installed under the vehicle body 1. In the present embodiment, the vehicle includes multiple seats, but may include one seat. In addition, it is assumed that the vehicle is a four-wheeled vehicle as an example, but the present invention is also applicable to a vehicle including at least one front wheel and at least one rear wheel.

[0012] A suspension device 4 on the front wheel side is mounted between the front left wheel 2 side and the front right wheel 2 side, and the vehicle body 1, respectively. Suspension device 4 on the front wheel side includes left and right suspension springs 5 (hereinafter referred to as springs 5), and shock absorbers 6, sensitive to the stroke of the rod, as left and right shock absorbers with variable mechanical damping force installed between the sides of the front left and the right wheels 2 and the vehicle body 1 in parallel with these respective springs 5 (hereinafter referred to as the dampers 6, sensitive to the stroke of the rod), respectively.

[0013] As used herein, the phrase "configured or configured to mechanically vary or adjust damping force" means "configured or configured to vary or adjust damping force without using an actuator." A mechanical shock absorber with a variable damping force includes, for example, a shock absorber in which the damping force automatically changes in accordance with the position of the stroke, and a shock absorber in which the damping force automatically changes in accordance with the vibration frequency, and does not include a shock absorber, where the damping force is not automatically changed by the actuator. In addition, a mechanical shock absorber with a variable damping force also does not include the so-called conventional type shock absorber, in which the damping force varies only in accordance with the piston speed.

[0014] As shown in FIG. 2, dampers 6, sensitive to the stroke, each includes an inner tube 11, an outer tube 12, a piston 15, a piston rod 21, a measuring pin 26, a return spring 30, mechanisms 33 and 34 for regulating the first and second displacement areas, mechanisms 35 and 36 damping force generation on the expansion side and the compression side, and the like. Due to this configuration, each of the left and right dampers 6, sensitive to the stroke, each has the function of improving performance when damping vibration in the return direction, reducing the rigidity of the vehicle body 1 in the roll direction on the side of the front left and right wheels 2.

[0015] The suspension device 7 on the rear wheel side is mounted between the sides of the rear left and right wheels 3 and the vehicle body 1, respectively. The suspension device 7 on the side of the rear wheels includes left and right suspension springs 8 (hereinafter referred to as spring 8), and the left and right shock absorbers 9 with damping control are mounted between the sides of the rear left and right wheels 3 and the vehicle body 1 in parallel with this corresponding springs 8 (hereinafter referred to as dampers 9 with damping force control), respectively. An electronically controlled actuator 9A including a damping force control valve, a solenoid, and the like. (see Fig. 5) is installed on each of the dampers 9 with control of the damping force to ensure the possibility of constant regulation of its characteristics of the damping force from a rigid characteristic (high damping force) to a soft characteristic (weak damping force).

[0016] The damping force characteristic of the damper 9 with damping force control is variably controlled in accordance with a control signal output from the controller 51, which will be described later, to the actuator 9A. More specifically, the damping force generated by the damping force control damper 9 is variably controlled by the actuator 9A in accordance with, for example, the conditions in which the vehicle is traveling, which include the road surface condition. The actuator 9A, which controls the damping force, does not have to be configured to continuously change the characteristics of the damping force, and can be configured to regulate the intermittent adjustment of the damping force in two stages or three or more stages.

[0017] Next, with reference to FIG. 2, the configuration of the stroke-sensitive damper 6 will be described as a shock absorber with a variable mechanical damping force mounted on the side of the front wheel 2 of the vehicle.

[0018] The stroke-sensitive damper 6 is configured, for example, as a so-called double-tube type hydraulic shock absorber, and includes a cylindrical cylinder 11 (hereinafter referred to as the inner tube 11) in which the oil fluid is hermetically contained, as a hydraulic fluid, and having a bottom, a cylindrical outer tube 12, formed to have a larger diameter than the inner tube 11, and concentrically mounted so that it closes the inner tube 11 from the outside.

[0019] A tank chamber 13, which seals gas together with the oil fluid contained therein, is formed between the inner tube 11 and the outer tube 12. A mounting eye 14 is provided on the lower side of the outer tube 12. Such a mounting eye 14 constitutes a mounting member, mounted on the outer tube 12 of the damper 6, sensitive to the stroke, for the side of the front wheel 2 of the vehicle.

[0020] The piston 15, like a movable partition, is installed in the inner tube 11 with the possibility of its sliding movement. Such a piston 15 divides (delimits) the inner and outer tubes 11 into two chambers, a chamber 16 on the side of the rod located on the upper side and a chamber 17 on the lower side located on the lower side. Oil channels 15A and 15B that communicate between the chamber 16 on the side of the stem and the chamber 17 of the lower side through the damping force generating mechanisms 35 and 36, which will be described later, are formed through the piston 15. The oil fluid is sealed in the chamber 16 on the side the rod and in the chamber 17 of the lower side, and compressible gas, is hermetically contained in the reservoir 13 between the inner tube 11 and the outer tube 12, together with the oil fluid. Such a gas may be air at atmospheric pressure or may be compressed nitrogen gas.

[0021] The rod guide 18 and the oil seal 19 are located on the sides of the upper end of the inner tube 11 and the outer tube 12 (hole on one axial side). The upper end of the outer tube 12 is radially bent inward by crimping, and installs the rod guide 18 and the oil seal 19, clamping them between the upper end of the outer tube 12 and the upper end of the inner tube 11. The rod guide 18 is operable to slide the stem 21 the piston, which will be described below, and directs the expansion of the piston rod 21 outward from the inner tube 11 and the outer tube 12, and the reduction of the piston 21 of the rod into the inner tube 11.

[0022] On the other hand, the lower valve 20 for generating damping forces is located on the sides of the lower end of the inner tube 11 and the outer tube 12 (lower side opposite to the axial side). This lower valve 20 functions to detect the lower side chamber 17 in the inner tube 11 and the tank chamber 13 in the outer tube 12, being placed on the lower side of the outer tube 21, and generates a damping force by the oil fluid flowing between the stem side and the chambers 13 and 17 bottom sides.

[0023] The side of the upper end (one end) of the piston rod 21 extending along the axis (vertically) in the inner tube 11 extends so that it protrudes from the inner tube 11 and from the outer tube 12 through the rod guide 18 and the oil seal 19. Side the lower end (opposite end) of the piston rod 21 is connected (fixed) to the piston 15 in the inner tube 11 through, for example, a nut 24, which will be described below, and this connection allows the piston 15 to be moved together with the piston rod 21 in the inner tube 11.

[0024] The piston rod 21 includes a rod main body 22 inserted on the inside of the circumference of the rod guide 18 and the oil seal 19, and extending from the inner tube 11 and the outer tube 12, and a connecting rod 23 threaded to the lower side the end (with the end on the opposite side located in the inner tube 11) of the stem main body 22 and integrally connected to the stem main body 22. The nut 24 is threadedly connected to the lower end side of such a connecting rod 23, which allows the piston 15 to be fixed on the connecting rod 23 (i.e., on the piston rod 21).

[0025] An axial hole 22A that is located along the axis is formed in the radial center of the stem main body 22. A through hole 23A, which extends along the axis concentrically with the axial hole 22A, is formed in the radial center of the connecting rod 23. The axial hole 22A of the main rod body 22 has a lower end side in communication with a through hole 23A of the connecting rod 23, and an upper end side extending to intermediate position in the immediate vicinity of the protruding end of the main rod body 22, and closed from the outside.

[0026] An axial bore 22A of the stem main body 22 and a through hole 23A of the connecting rod 23 form a pin insert hole 21A in the piston rod 21. The measuring pin 26, which will be described later, is inserted into this pin insertion hole 21A so that it moves relative to the piston rod 21 and a radial space is formed between them. An internal rod channel 25 (i.e., an oil flow channel) that allows oil to flow through it inside the piston rod 21 is formed between the pin insertion hole 21A and the measurement pin 26.

[0027] An annular protrusion 24A that projects radially inward is provided on the side of the lower end (opposite end) of the nut 24. Such an annular protrusion 24A is formed so that the size of its inner diameter generally corresponds to an axial portion 26A with a larger diameter of the measuring pin 26 to be described below. The annular protrusion 24A of the nut 24 forms a second channel region control mechanism 34, which will be described below, between the annular protrusion 24A and the outer circumferential surface of the measuring pin 26, and has the function of variablely adjusting the channel region of the inner channel 25 of the rod relative to the lower side chamber 17 through the measuring pin 26 .

[0028] The side of the lower end (end of the side of the lower valve 20) of the measuring pin 26 is fixed to the central side of the lower valve 20 through the holder member 27 and the like, and is mounted vertically upward in the direction of the pin insertion hole 21A of the piston rod 21. Due to this arrangement, the side of the upper end of the measuring pin 26 is inserted into the pin insertion hole 21A in the piston rod 21, and the small diameter axial portion 26C, which will be described later, continues into the axial hole 22A of the rod main body 22. The measuring pin 26 includes a large diameter axial portion 26A located closer to its proximal end side (lower side) and formed cylindrically, a conical axial portion 26B extending from the upper end of this large axial portion 26A with an upward axis, tapering conically, and an axial portion 26C with a small diameter having a free end at the distal end along the axis upward and cylindrically extending from the upper end of the conical axial portion 26B.

[0029] The large diameter axial portion 26A of the measuring pin 26 is formed so that its outer diameter generally corresponds to the inner diameter of the ring protrusion 24A of the nut 24. Therefore, when the piston rod 21 is inserted into the inner tube 11, and the axial portion 26A with a large diameter of the measuring pin 26 is located on the radially inner side relative to the nut 24 (ring protrusion 24A), as shown in FIG. 2, the passage area of the inner stem passage 25 is set as a minimum area by the second passage area control mechanism 34, which will be described below, so that the inner stem passage 25 is brought into a state substantially controlling the flow of oil fluid and disconnected from and close relative to the camera 17 of the lower side.

[0030] The spring support 28 on the piston side is provided in a position offset upward from the piston 15 by a predetermined distance (for example, in a position in which the connecting rod 23 is fixed to the stem main body 22) on the outer circumference of the stem main body 22 for the stem 21 piston. In addition, the spring support 29 on the side of the rod guide is provided in the up position, offset from this spring support 28 on the piston side by a predetermined distance, on the outer circumference side, on the side of the stem main body 22. The main body 22 of the rod is inserted on the respective inner sides of the circumference of the spring support 28 on the piston side and the spring support 29 on the side of the guide rod so that the spring support 28 on the piston side and the spring support 29 on the side of the rod guide are mounted with axial relative displacement (sliding) ) along the surface of the outer circumference of the main body 22 of the rod.

[0031] A return spring, which is in the form of a coil spring, is located between the spring support 28 on the piston side and the spring support 29 on the stem guide side, which allows the stem main body 22 to be inserted inside it. A damping element 31, which is made of an annular elastic material, is provided on the side of the upper surface of the spring support 29 on the side of the rod guide in a position opposite to the return spring 30. Such a damping element 31 is also fixed to slide along the outer circumference of the main body 22 of the rod, due to its location so that it is possible to insert the main body 22 of the rod through it.

[0032] When the piston rod 21 extends substantially upward from the outer tube 12, the spring support 29 on the side of the rod guide is adjacent to the lower surface of the rod guide 18 through the damping element 31, and the return spring 30 is elastically deflected and deformed so that it does not deform with compression between the spring support 28 on the piston side and the spring support 20 on the side of the rod guide. The side of the protruding end of the piston rod 21 is connected, for example, to the side of the vehicle body 1, and the lower side of the outer tube 12 is connected to the side of the wheel (front wheel 2) through the mounting eye 14.

[0033] A radial channel opening 32 and a first channel area adjustment mechanism 33 are provided on the connecting rod 23 of the piston rod 21 in a position below the spring support 28 on the piston side. The channel opening 32 is a channel that establishes a message between the camera 16 on the side of the rod and the internal channel 25 of the rod, and the first channel area adjustment mechanism 33 is operable to vary the channel area of the channel opening 32 (i.e., the area of the channel between the camera 16 to side of the rod and the inner channel 25 of the rod), in accordance with the position of the stroke of the piston rod 21.

[0034] In other words, the area of the channel between the chamber 16 on the side of the rod and the inner channel 25 of the rod is changed by the first mechanism 33 for adjusting the area of the channel, in accordance with the bias force of the return spring 30, changing in accordance with the position of the stroke of the piston rod 21. The channel area at this time is set in such a way that it increases when the bias force of the return spring 30 is weak, and decreases with a gradual increase in the bias force, so that it eventually drops to zero and the channel closes.

[0035] An annular protrusion 24A of the nut 24, which is threaded to the side of the lower end of the connecting rod 23, forms a second channel area control mechanism 34 between the annular protrusion 24A and the outer circumference of the measuring pin 26. The measuring pin 26 includes an axial portion 26A of a large diameter, located closer to the side of the proximal end, a conical axial section 26B, and an axial section 26C of small diameter, the free end of which is located at its distal end. Therefore, the second channel area adjusting mechanism 34 functions so that it alternately adjusts the channel area (flow area of the channel) of the inner channel 25 of the rod with respect to the lower side chamber 17, depending on which portion is located on the inner circumference of the annular protrusion 24A of the nut 24 among the axial sections 26A-26C of the measuring pin 26.

[0036] More specifically, when the piston rod 21 is compressed so that it substantially moves inside the inner tube 11, and the axial portion 26A of the large diameter of the measuring pin 26 is located on the inner circumference of the nut 24 (ring protrusion 24A), the second mechanism 34 adjusting the area of the channel adjusts the area of the channel of the inner channel 25 of the rod relative to the chamber 17 of the lower side so as to minimize this area so as to substantially block the flow of oily fluid through it.

[0037] On the other hand, when the piston rod 21 moves down to an intermediate position and the conical axial portion 26B of the measuring pin 26 is located on the inner circumference of the nut 24 (annular protrusion 24A), the second channel area adjustment mechanism 34 adjusts the channel area for the internal channel 25 of the rod relative to the chamber 17 of the lower side, gradually increasing this area in accordance with the expansion of the piston rod 21. In addition, when the piston rod 21 extends substantially outside the outer tube 12, and the axial portion 26C with the small diameter of the measuring pin 26 is located on the inner circumference of the nut 24 (annular protrusion 24A), the second channel area control mechanism 34 adjusts the channel area for the inner channel 25 of the rod relative to the camera 17 of the lower side, in order to maximize this area.

[0038] The expansion side damping force mechanism 35 that generates damping force during the expansion stroke in accordance with the expansion side of the piston rod 21, and the compression side damping force mechanism 36 that generates the damping force during the stroke with a tap, in accordance with the tap side of the piston rod 21, are provided in the piston 15 in the inner tube 11. The damping force generating mechanism 35 on the expansion side is located on the lower side of the chamber 17 thoron which corresponds to the lower side (an opposite axial side) of the piston 15. The mechanism 36 for generating a damping force on the compression side is located on the side of the chamber 16, on the side of the rod, which corresponds to the upper side (one axial side) of the piston 15.

[0039] As shown in FIG. 2 and 3, the expansion-side damping force generating mechanism 35 includes a pilot-type hydraulic damping valve 38 including a pilot chamber 37 between the damping valve 38 and the piston 15, an opening 39 provided between the inner shaft channel 25 and the pilot chamber 37, and a disk valve 40 and a hole 41 located parallel to each other between the pilot chamber 37 and the lower side chamber 17.

[0040] Furthermore, a radial channel opening 42 that establishes communication between the inner channel 25 of the rod and the pilot chamber 37 is formed on the connecting rod 23 of the piston rod 21, and this channel opening 42 is connected to the pilot chamber 37 through the opening 39. Valve opening pressure the hydraulic damping valve 38 of the pilot type is set so that it changes in accordance with the pressure in the pilot chamber 37. Then, when the damping valve 38 is opened, the oily fluid in the chamber 16 on the side of the leakage rod emits into the chamber 17 of the lower side through the oil channel 15A of the piston 15.

[0041] The compression-side damping force generating mechanism 36 includes a pilot-type hydraulic damping valve 44, including a pilot chamber 43 between the damping valve 44 and the piston 15, an opening 45 provided between the inner channel 25 of the rod and the pilot chamber 43, and a disk valve 46 and a hole 47 parallel to each other between the pilot chamber 43 and the chamber 16 on the stem side.

[0042] Furthermore, a radial channel opening 48 that establishes a communication between the inner channel 25 of the rod and the pilot chamber 43 is formed on the connecting rod 23 of the piston rod 21, and this channel opening 48 is connected to the pilot chamber 43 through the opening 45. Valve opening pressure the hydraulic damping valve 44 of the pilot type is set so that it changes in accordance with the pressure in the pilot chamber 43. Then, when the damping valve 44 is opened, the oily fluid in the chamber 17 of the lower side leaks t into the chamber 16 on the side of the rod through the channel 15B for oil piston 15.

[0043] As indicated in the hydraulic circuit diagram shown in FIG. 3, the stroke-sensitive damper 6 is configured such that the damping force generating mechanism 35 on the side of its movement and the damping force generating mechanism 36 on the compression side are parallel to each other between the camera 16 on the rod side and the lower side camera 17. The inner channel 25 of the rod in the piston rod 21 is communicated by the camera 16 of the rod through the first mechanism 33 for regulating the area of the channel, the channel area of which is variablely regulated by the return spring 30 and the like, and communicates with the camera 17 on the lower side through the second mechanism 34 for regulating the area of the channel, having channel area, variable adjustable by measuring pin 26, etc.

Then, the pilot chamber 37 of the expansion-side damping force generating mechanism 35 communicates with the inner channel 25 of the rod through the opening 39 and the channel opening 42, and the pilot chamber 43 of the compression-side damping force generating mechanism 36 communicates with the inner channel 25 of the rod through the hole 45 and the hole 48 channel.

[0044] The stroke-sensitive damper 6 includes a communication channel that establishes a message between the two chambers, a chamber 16 on the side of the stem and a chamber 17 of the lower side, which allows an oily fluid, like a hydraulic fluid, to flow through it (including the piston 15 oil channels 15A and 15B, the rod internal channel 25, and the like), and the damping force generating device located in this channel and configured to generate the damping force by obstructing the flow of oily fluid caused by the movement of the piston 15. Such a damping force generating device includes the first and second channel area adjusting mechanisms 33 and 34 described above, and the damping force generating mechanisms 35 and 36 described above on the expansion side and the compression side.

[0045] As a result of this configuration, the stroke-sensitive damper 6 significantly changes the damping force on the expansion side in the region of the stroke stroke position S1, as indicated by the characteristic line 49, which is drawn by the solid line in FIG. 4, and significantly changes the damping force on the compression side around the position S2 (S2> S1) of the stroke, as indicated by the characteristic line 50, drawn as a dashed line in FIG. four.

[0046] In this case, the range on the right side located on the side of further extension (Reb) of the stroke S2 of the stroke shown in FIG. 4 corresponds to a predetermined range on the maximum length side, where the piston rod 21 protrudes from the inner tube 11 beyond the specified position of the maximum length side, and has such a characteristic of the maximum length side that the damping force on the expansion side is set to a soft state, as indicated by line 49 characteristics drawn by a solid line in FIG. 4, and the rigid state of the damping force on the compression side is set, as indicated by the characteristic line 50 drawn by the dashed line in FIG. 4. According to this characteristic, on the maximum length side, the damping force on the expansion side is set to a soft state, and the damping force on the compression side is set to a rigid state, regardless of whether the piston speed is slow or fast.

[0047] On the other hand, the range on the left side located on the high compression (Comp) side is outside the stroke travel position S1 shown in FIG. 4 corresponds to a predetermined range of the minimum length side, where the piston rod 21 enters the inner tube 11 beyond a predetermined position on the minimum length side, and has such a characteristic of the minimum length side such that the damping force on the expansion side is set to a rigid state, as indicated by line 49 characteristics drawn by a solid line in FIG. 4, and the damping force on the compression side is set to a soft state, as indicated by the characteristic line 50 drawn by the dashed line in FIG. 4. According to this minimum length characteristic, the damping force of the expansion side is set to a rigid state, and the damping force of the compression side is set to a soft state, regardless of whether the piston speed is slow or fast.

[0048] In other words, the stroke-sensitive damper 6 includes first and second channel area adjusting mechanisms 33 and 34, which adjust the channel area for the communication channel, in accordance with the position of the stroke of the piston rod 21, together with mechanisms 35 and 36 generating damping forces on the expansion side and on the compression side, in order to have at least any one of the characteristics of the maximum length side, according to which the damping force on the expansion side is set to soft the state and damping force on the compression side is set to a rigid state in the range where the piston rod 21 protrudes from the inner tube 11 beyond a predetermined position on the maximum length side (e.g., position S2), and minimum length characteristics, according to which the damping force on the expansion side is set to a rigid state, and the damping force on the compression side is set to a soft state in the range where the piston rod 21 enters the inner tube 11 beyond a predetermined position on the side of the minimum length (e.g., the position S1).

[0049] Next, with reference to FIG. 5, the configuration of the damper 9 with damping force control mounted on the rear wheel side 3 of the vehicle will be described. The control signal is output from the controller 51, used as a control device, into the actuator 9A of the damper 9 with damping force control, and the damper 9 with damping force control is operating at this time for variable control of the damping force, in accordance with the control signal.

[0050] More specifically, the damping force generated by the damper 9 with damping force control is variably controlled by the actuator 9A in accordance with, for example, the conditions under which the vehicle is moving, which includes the road surface condition. The controller 51 includes, for example, a microcomputer. The input side 51 of the controller is connected to a spring-loaded acceleration sensor 52, a rotation angle sensor 53, and the like. The output side of the controller 51 is connected to the actuator 9A of the damper 9 with damping force control, etc.

[0051] A spring-loaded acceleration sensor 52 provided on the vehicle body 1 is mounted on the vehicle body 1 in a position in close proximity to the damper 9 with damping force control to detect vertical vibrational acceleration of the vehicle body side, which corresponds to the so-called spring side. Then, the spring-loaded acceleration sensor 52 detects the vertical vibrational acceleration of the body 1 and outputs a signal of such detection to the controller 51. The rotation angle sensor 53 is mounted on the side of the vehicle body 1. The rotation angle sensor 53 functions to detect a rotation angle when the vehicle driver performs a steering operation (not shown), trying, for example, to turn the vehicle, and outputs such a detection signal to the controller 51.

[0052] More specifically, the controller 51 reads the vehicle driving conditions from the spring-loaded acceleration sensor 52, the steering angle sensor 53, and the like, and outputs a control signal to the electronically controlled actuator 9A to improve the maneuvering stability and vehicle comfort. Then, the damper 9 with the control of the damping force is made with the possibility of variable installation, for example, the lateral stiffness of the suspension of the vehicle body 1 on the side of the rear wheel 3 to increase or decrease it using electronic control, in accordance with the control signal output from the controller 51.

[0053] More specifically, the damping force control damper 9 is configured to alternately control the damping force on the rear wheel side 3 using the actuator 9A so that the angle of heel of the vehicle body 1 increases when the driver controls the vehicle, the pitch angle is the direction of the front side of the vehicle is increased to orient the vehicle body 1 into a position with the front portion tilted. The damper 6, sensitive to the stroke on the side of the front wheel 2, is made at this time with the ability to allow the orientation of the vehicle body 1 in a position with a longitudinal inclination in the direction of the front side on the side 2 of the front wheel of the vehicle.

[0054] A four-wheeled vehicle, which is a subcompact, in accordance with the present embodiment, is configured as described above. Next will be described the operation of the damper 6, sensitive to the stroke installed on the side 2 of the front wheel of the vehicle.

[0055] When the damper 6, sensitive to the stroke, is in a predetermined range of the maximum length side, where the piston rod 21 extends beyond the inner tube 11 beyond a predetermined position on the maximum length side (for example, the position S2 of the stroke shown in Fig. 4 ), the damping element 31 is adjacent to the rod guide 18, and the return spring 30 is deflected and deformed so that it is elastically compressed. As a result, the first channel region adjusting mechanism 33 closes the radial channel hole 32 formed on the connecting rod 23 so that it disconnects the radial channel hole 32 from the camera 16 on the rod side.

[0056] Furthermore, in this predetermined range of the maximum length side, the second channel region adjusting mechanism 34 provides a maximum channel area for the rod inner channel 25 by installing an axial portion 26C with a small diameter of the measuring pin 26 on the radially inner side of the nut 24 (annular protrusion 24A). In such a predetermined side range of the maximum length side, the inner channel 25 of the rod communicates with the lower side camera 17 through the second channel region adjusting mechanism 34, and both the pilot chamber 37 of said damping force generating mechanism 35 on the expansion sides and the pilot chamber 43 of the force generating mechanism 36 damping on the compression side communicates with the camera 17 of the lower side through the holes 42 and 48 of the channels, the inner channel 25 of the rod and the second mechanism 34 for regulating the area of the channel.

[0057] In this predetermined range of the maximum length side, during the expansion stroke, in which the piston rod 21 protrudes from the inner tube 11, the piston 15 slides upward toward the chamber 16 on the rod side, resulting in pressure in the chamber 16 on the side of the rod increases, while the pressure in the chamber 17 of the lower side decreases. Therefore, the pressure in the chamber 16 on the side of the rod is applied to the damping valve 38 of the damping force generating mechanism 35 on the expansion side through the oil channel 15A on the expansion side and formed through the piston 15. At this time, the pilot chamber 37, which applies the pilot pressure to the damping the valve 38 in the direction of closing the valve, communicates with the camera 17 of the lower side through the hole 42 of the channel, the inner channel 25 of the rod, and the second mechanism 34 for regulating the area of the channel. Therefore, the pilot chamber 37 is introduced into a pressure state close to the lower side chamber 17, and the pilot pressure therein is reduced.

[0058] As a result, the damping valve 38 is relatively easily detached from the valve seat, opening in accordance with a decrease in the pilot pressure received from the pilot chamber 37, thereby allowing the oily fluid to flow from the chamber 16 on the stem side into the lower side chamber 17 . As a result of this possibility, the damping force of the damping force generating mechanism 35 on the expansion side is reduced on the side of the stroke position S2, thereby setting the damping force on the expansion side to a soft state, as indicated by the characteristic line 49 drawn by a solid line in FIG. . four.

[0059] On the other hand, in this predetermined range of the maximum length side, during the compression stroke in which the piston rod 21 enters the inner tube 11, the piston 15 slides downward towards the lower side chamber 17, resulting in pressure in the chamber 17 of the lower side increases, while the pressure in the chamber 16 of the rod decreases. Therefore, hydraulic oil in the lower side chamber 17 is applied to the damping valve 44 of the compression side damping force generating mechanism 36 through the compression side oil channel 15B formed through the piston 15. At this time, the pilot chamber 43, which applies pilot pressure to the valve 44 damping in the closing direction of the valve is in communication with the lower side chamber 17 through the channel opening 48, the rod internal channel 25 and the second channel area adjustment mechanism 34. Therefore, the pilot chamber 43 is brought into a pressure state close to the lower side chamber 17, and the pilot pressure therein increases with increasing pressure in the lower side chamber 17.

[0060] In this state, when the piston speed is low, the increase in pressure in the pilot chamber 43 may follow the increase in pressure in the lower side chamber 17, as a result of which the damping valve 44 is brought into a state of difficult detachment from the valve seat in accordance with the increase pressure in the pilot chamber 43. Therefore, the oily fluid from the lower side chamber 17 flows through the pilot chamber 43 from the second channel area control mechanism 34, the rod’s inner channel 25 and the channel opening 48, and flows into the chamber 16 at The rod is threaded through the hole 47, in parallel with the disk valve 46, thereby generating a damping force in accordance with the characteristic of the hole (the damping force is generally proportional to the square of the piston speed). Therefore, the damping force has such a characteristic with respect to the piston speed that the damping force increases at a relatively higher speed relative to the increase in the piston speed.

[0061] Furthermore, even when the piston speed is higher than described above, the damping valve 44 is also in a state of difficult separation from the valve seat, and the oily fluid from the lower side chamber 17 flows through the pilot chamber 43 from the second area adjustment mechanism 34 the channel, the inner channel 25 of the rod and the hole 48 of the channel and flows into the chamber 16 on the side of the rod, opening the valve 46 of the disk, thus generating a damping force in accordance with the valve characteristic (the damping force is generally proportional to spine of the piston). Therefore, the damping force has such a characteristic with respect to the piston speed that the damping force increases with a slightly lower speed relative to the increase in the piston speed.

[0062] Thus, the damping force generated by the compression side damping force generating mechanism 36 during the compression stroke is higher than the damping force during the expansion stroke (line 49 of the characteristic drawn by a solid line) on the position side S2 of the stroke as indicated by the characteristic line 50 drawn by the dashed line of FIG. 4, and the damping force on the compression side generated by the damping force generating mechanism 36 is set to a rigid state.

[0063] Even during the compression stroke in a predetermined range, the sides of the maximum length, as soon as the piston speed reaches a further high-speed region, for example, when a shock / push occurs, due to the uneven surface of the road, etc., an increase in pressure in the pilot the chamber 43 loses its ability to track the increase in pressure in the chamber 17 of the lower side. Regarding the relationship between the forces based on the differential pressure applied to the damping valve 44 of the compression side damping force generating mechanism 36, the force applied to the oil channel 15B formed through the piston 15 in the direction of the valve opening exceeds the force applied from the pilot chamber 43 in the direction of closing the valve. Therefore, in this area, the damping valve 44 opens, separating from the valve seat, in accordance with an increase in the piston speed, as a result of which the increase in the damping force is stopped or reduced.

[0064] The damping force at this time has such a characteristic with respect to the piston speed that the damping force increases with almost zero speed relative to the increase in piston speed. Therefore, for example, when a shock / jerk occurs due to an uneven surface of the road or the like, which results in a fast piston speed and a relatively high frequency, the damping force generating device prevents an increase in damping force, or provides a smaller increase in damping force relative to increasing the speed of the piston, as described above, thus leading to sufficient shock absorption.

[0065] Thus, the range on the right side located on the side of the additional extension (Reb) outside the position S2 of the stroke shown in FIG. 4 (the right side in FIG. 4) corresponds to a predetermined range on the maximum length side, where the piston rod 21 protrudes from the inner tube 11 beyond the specified position of the maximum length side, and has such a characteristic of the maximum length side that the damping force on the expansion side is set to the soft state, as indicated by the characteristic line 49, which is drawn by a solid line in FIG. 4, and the damping force on the compression side is set to a rigid state, as indicated by the characteristic line 50 drawn by the dashed line in FIG. 4. According to this characteristic, on the maximum length side, the damping force on the expansion side is set to a soft state, and the damping force on the compression side is set to a rigid state, regardless of whether the piston speed is slow or fast.

[0066] Further, the predetermined position on the minimum length side, where the piston rod 21 enters the inner tube 11 outside the predetermined position on the minimum length side (for example, the stroke position S1 shown in Fig. 4), the return spring 30 enters the free state lengths as shown in FIG. 2, without elastic deformation (compression), so that the mechanism 33 for controlling the first channel region will not be compressed by the bias force from the side of the return spring 30, thereby forming the maximum channel area determined by the first channel area adjustment mechanism 33 to maintain communication between a channel radial hole 32 formed on the connecting rod 23 and in the chamber 16 on the side of the rod.

[0067] Furthermore, in a predetermined minimum length range, an axial portion 26A with a large diameter of the measuring pin 26 is mounted on the radial inner side of the nut 24 (annular protrusion 24A), whereby the second channel area adjustment mechanism 34 sets the channel area for the internal channel 25 rod, as the minimum area for disconnecting the inner channel 25 of the rod from the camera 17 of the lower side and the closure of the internal channel 25 of the rod relative to the camera 17 of the lower side. However, in this predetermined range on the minimum length side, the inner channel 25 of the rod communicates with the camera 16 on the rod side through the opening of the channel 32 described above, and both the pilot chamber 37 of the damping force generating mechanism 35 on the expansion side and the pilot chamber 43 of the mechanism 36 the generation of damping forces on the compression side communicate with the camera 16 on the rod side through the holes 42 and 48 of the message, the inner channel 25 of the rod and the hole 32 of the channel.

[0068] During the expansion stroke, in which the piston rod 21 extends from the inner tube 11 in its predetermined range on the minimum length side, the piston 15 slides upwardly towards the side of the chamber 16 on the stem side, resulting in pressure in the chamber 16 on the side of the rod increases, while the pressure in the chamber 17 of the lower side decreases. Therefore, pressure in the chamber 16 on the stem side is applied to the damping valve 38 of the expansion side damping force mechanism 35 through the oil side 15A on the expansion side formed through the piston 15. At this time, the pilot chamber 37, which applies pilot pressure to the damping valve 38 in the direction of closing the valve, communicates with the camera 16 on the side of the rod through the hole 42 of the channel, the inner channel 25 of the rod and the hole 32 of the channel. Therefore, the pilot chamber 37 is brought into a pressure state close to the chamber 16 on the stem side, and the pilot pressure therein rises in accordance with the increase in pressure in the chamber 16 on the stem side.

[0069] In this state, when the piston speed is low, an increase in pressure in the pilot chamber 37 can lead to an increase in pressure in the chamber 16 on the stem side, as a result of which the damping valve 38 can be brought into a state in which it is difficult to separate from the socket valve, due to a decrease in the adopted differential pressure. Therefore, the oily fluid from the chamber 16 on the stem side flows through the pilot chamber 37 from the channel opening 32, the inner channel 25 of the rod and the channel opening 42 and flows into the lower side chamber 17 through the opening 41 parallel to the disk valve 40, thereby generating a force damping, in accordance with the characteristic of the hole (the damping force is generally proportional to the square of the piston speed). Therefore, the damping force has such a characteristic with respect to the piston speed that the damping force increases with a relatively high speed relative to the increase in the piston speed.

[0070] Furthermore, even when the piston speed is higher than described above, the oily fluid in the chamber 16 on the stem side flows through the pilot chamber 37 from the channel opening 32, the internal channel 25 of the rod and the channel opening 42 without separating the damping valve 38 from the socket valve, and flows into the chamber 17 of the lower side, opening the disk valve 40, thus generating a damping force in accordance with the characteristic of the valve (the damping force is generally proportional to the piston speed). Therefore, the damping force has such a characteristic with respect to the piston speed that the damping force increases with a slightly lower speed relative to the increase in the piston speed. Thus, a large damping force is generated during the expansion stroke, setting the damping force on the expansion side to a rigid state.

[0071] On the other hand, during the compression stroke, in which the piston rod 21 enters the inner tube 11 in this predetermined range on the minimum length side, the piston 15 slides downward towards the lower side chamber 17, resulting in pressure in the chamber 17 of the lower side increases, while the pressure in the chamber 16 on the side of the rod decreases. Therefore, hydraulic oil in the lower side chamber 17 is applied to the damping valve 44 of the compression side damping force mechanism 36 through the compression side oil channel 15B formed through the piston 15. At this time, the pilot chamber 43, which applies pilot pressure to the damping valve 44 in the direction of closing the valve, communicates with the camera 16 on the side of the rod through the hole 48 of the channel, the inner channel 25 of the rod and the hole 32 of the channel. Therefore, the pilot chamber 43 is brought into a pressure state close to the chamber 16 on the stem side, and the pilot pressure therein decreases. Therefore, the damping valve 44 begins to take on a higher differential pressure for relatively simple separation from the valve seat, which is to open, thus allowing the oily fluid to flow towards the side of the chamber 16 on the stem side. As a result, a weaker damping force is generated during the compression stroke than the damping force generated during the expansion stroke, setting the damping force on the compression side to a soft state.

[0072] Thus, the range located further on the compression side beyond the position S1 of the stroke shown in FIG. 4 (the left side in FIG. 4) corresponds to a predetermined range on the minimum length side, where the piston rod 21 enters the inner tube 11 outside the predetermined position of the minimum length side, and has a minimum length side characteristic such that the damping force on the expansion side is set to the hard state, as indicated by the characteristic line 49, drawn by the solid line in FIG. 4, and the damping force on the compression side is set to a soft state, as indicated by the characteristic line 50 drawn by the dashed line in FIG. 4. In accordance with this characteristic of the shortest side, the damping force of the expansion side is set to a rigid state, and the damping force of the compression side is set to soft standing, regardless of whether the piston speed is slow or fast. Furthermore, for example, when the piston rod 21 is in the neutral position, the damping force on the expansion side is set to the middle state, and the damping force on the compression side is set to the soft state, regardless of whether the piston speed is fast or slow.

[0073] Next, an operation of the damper 9 with controlling the damping force mounted on the rear wheel side 3 of the vehicle will be described. The damper 9 for controlling the damping force is configured to vary, for example, the roll stiffness of the vehicle body 1 on the rear wheel side 3, to increase or decrease it using electronic control, in accordance with the control signal output from the controller 51. More specifically, the controller 51 reads the conditions in which the vehicle is moving from the spring-loaded acceleration sensor 52, the angle sensor 53, and the like, and outputs a control signal to the actuator 9 with electronic control We use it to improve the stability of maneuvering and vehicle comfort.

[0074] This configuration allows the damping force 9 to control the damping force on the side of the rear wheel 3 using the actuator 9A in such a way that, as the angle of heel of the vehicle body 1 increases when the driver controls the vehicle , the longitudinal inclination angle towards the front side of the vehicle is increased to orient the vehicle body 1 in the lowered front position. At this time, the damper 6, sensitive to the stroke on the side of the front wheel 2, is configured to set the orientation of the vehicle body 1 to a position with a lowered front on the side of the front wheel 2 of the vehicle.

[0075] Thus, the stiffness of the roll on the side of the front wheel 2 is set to a lower value, and the stiffness of the roll on the side of the rear wheel 3 is set to a higher value, which leads to the so-called diagonal roll, thereby improving the response off course when the driver drives the vehicle. More specifically, a stroke sensitive damper 6 that provides low roll stiffness is used on the front wheel 2 side, and a damping force damper 9 that can control roll stiffness to an appropriate degree using electronic control is used on the rear side 3 wheels, as a result of which, the sensitivity to control operations can be significantly improved compared to a vehicle, in accordance with conventional technology, and not an expensive damper 6, senses The power to the stroke can be used on the side of the front wheel 2 together with an expensive damper 9 with damping force control, which is used only on the side of the rear wheel 3. As a result, for example, the number of electric wires in the vehicle body and the number of circuits controlled ECU, as a result, the system can be simplified.

[0076] In FIG. 6 illustrates data obtained from a test performed by actual vehicles, that is, characteristic lines 54-57 are illustrated, each of which represents a rotation angle characteristic or a yaw rate characteristic of a moving vehicle. The characteristic line 54, drawn by a dot-dash line with two points, represents a characteristic of the angle of rotation, which corresponds to the operation performed on the steering wheel when the driver repeatedly changes the lane while the vehicle is moving. The characteristic line 55, drawn by a solid line, represents the angular yaw rate characteristic of the vehicle to which the present invention is applied during such an operation performed with the steering wheel (characteristic line 54).

[0077] On the other hand, the characteristic line 56, drawn by the dashed line, represents the angular yaw rate characteristic in the first comparative example, using dampers similar to the damper 9 with damping force control, both from the front wheel side and the rear wheel side (below called an example using a semi-active damper on each of the four wheels). The characteristic line 57, drawn by a dashed line, represents the yaw rate characteristic, as a second comparative example, using general purpose shock absorbers (dampers, each of which has a damping force characteristic pre-adjusted for the average characteristic), both on the front wheel side and on the side of the rear wheel (hereinafter referred to as an example of a conventional type).

[0078] The characteristic lines 55, 56 and 57, illustrated in FIG. 6 also represent that excellent yaw rate characteristics can be achieved in a vehicle according to the present embodiment using a stroke sensitive damper 6 on the front wheel 2 side and a damper 9 with damping force control on the rear side wheels 3. In FIG. 7 shows, with an increase in part of the lines 55, 56 and 57, the characteristics indicated by arrow A in FIG. 6. As can also be seen in FIG. 7, the characteristic line 55 of the present embodiment shows a greater angular yaw rate when the driver turns the steering wheel (in close proximity to time t1) than the characteristic lines 56 and 57 corresponding to the first and second comparative examples, thereby achieving , characteristics, the most appropriate control operations.

[0079] More specifically, in accordance with the present embodiment, the stroke-sensitive damper 6 mounted on the front wheel 2 side provides only low rigidity in the direction of roll input in response to the control input, thereby generating significant roll at this time, but can set strong damping during roll back. Therefore, after the behavior of the vehicle body 1 is significantly changed, for example, when the driver returns the steering wheel, the present embodiment can effectively control the vibration of the vehicle body 1 and can also reduce the unstable behavior of the vehicle, thereby providing more smooth stabilization of the movement of the vehicle body 1 than in the second comparative example (characteristic line 57), which is an example of a conventional type.

[0080] Next, in FIG. 8 illustrates data obtained from a test performed for conventional vehicles, that is, characteristic lines 58-61 are presented, each of which represents a characteristic of a lateral roll angle and a pitch angle when a driver controls a vehicle while the vehicle is in motion. The characteristic line 58, drawn by a solid line, represents a characteristic of the roll angle and the pitch angle in the vehicle to which the present embodiment is applied.

[0081] On the other hand, the characteristic line 59, drawn by a dash-dot line with two dots, represents a characteristic of a roll angle and a longitudinal angle in an example using a semi-active damper on each of the four wheels (first comparative example). A characteristic line 60, drawn by a dashed line, represents a characteristic of a roll angle and a longitudinal angle in a second comparative example, which is an example of a conventional type. The characteristic line 61, drawn with a dash-dot line with two dots, is a characteristic in the third comparative example using a conventional type shock absorber on the front wheel 2 side and a semi-active damper 9 with damping force control on the rear wheel 3 side.

[0082] The present embodiment, using a damper 6 which is sensitive to the travel on the front wheel 2 side and a damper 9 with damping force control on the rear wheel side, allows a suspension system having a function similar to the first comparative example to be realized at a lower cost. represents an example using a semi-active damper on each of the four wheels (see line 59 of the characteristic drawn by a dot-dash line with two points in Fig. 8). In addition, an example that uses a semi-active damper on each of the four wheels allows you to adjust the comfort of movement and the stability of maneuvering the vehicle in accordance with each other, practically requiring the driver only to adjust the control parameter. On the other hand, the present embodiment includes a damper 6, sensitive to the stroke on the front wheel 2 side, and a semi-active damper on the rear wheel 3 side, and thus allows to realize a function similar to the example using a semi-active damper on each of four wheels, by adjusting the comfort of movement and the stability of maneuvering the vehicle in relation to both the control system and the mechanical system at the same time. This advantage cannot be achieved as a result of control that is carried out only by semi-active dampers mounted on two wheels.

[0083] On the other hand, the following difference can be seen when the present embodiment (see characteristic line 58 in FIG. 8) is compared with a third comparative example (see characteristic line 61 in FIG. 8) using a conventional type damper on the side front wheel 2 and semi-active shock absorber 9 with damping force control on the side of the rear wheel 3.

[0084] Compared with the present embodiment (characteristic line 58), the third comparative example (characteristic line 61 drawn by a dash-dot line with two dots in Fig. 8) cannot satisfactorily damp the roll on the side of the front wheel 2, thus preventing to stabilize the behavior of the vehicle body after the driver abruptly turns the steering wheel, so as to thereby lead to the obligatory corrective control operation. In addition, the third comparative example does not have a suspension function on the front wheel side, which prevents the side of the rear wheel from substantially introducing the suspension control function taking into account the balance between the front side and the rear side. As a result, compared with the present embodiment (the stroke-sensitive damper 6 on the front wheel 2 side), the third comparative example is very likely to lead to excessive vertical vibrations on the front wheel side, in particular on a bad road, and thus way, excessive throws on it, which, thus, greatly affects the comfort of movement.

[0085] In other words, the third comparative example easily leads to incomplete ride comfort, and has a characteristic similar to the second comparative example, which includes conventional type dampers on all four wheels (see the characteristic line 60, drawn with a dashed line in FIG. . 8). Compared to the second comparative example, which uses a conventional type damper on each of the four wheels, in the present embodiment, the longitudinal inclination angle also increases in response to the roll movement, as indicated by the characteristic line 58 drawn by a solid line, so that the present an embodiment implements diagonal behavior.

[0086] A third comparative example, which includes a conventional type damper on the front wheel side and a semi-active type damper on the rear wheel side (characteristic line 61 drawn by a dash-dot line with two points in Fig. 8) implements diagonal behavior, but also It includes the movement of the subsidence of the rear and does not stabilize the behavior after the driver returns the steering wheel after changing the lane. In the third comparative example (characteristic line 61), the vehicle presents the front lowering behavior when the driver starts to turn the corner, but presents significant rear subsidence behavior, due to insufficient damping force of the shock absorber (conventional type damper) on the front side wheels when the driver returns the steering wheel to its original state.

[0087] Furthermore, a four-wheeled vehicle, such as a small car in accordance with the present embodiment, is configured to use a damper 6 sensitive to the travel on the front wheel 2 side and a damper 9 with damping force control on the rear wheel 3 side. Such the configuration allows for a compact layout for a four-wheeled vehicle, even when the stroke-sensitive damper 6 mounted on the front wheel 2 side is used as a compressed element nt, and it has the advantage that such an arrangement contributes to obtaining.

[0088] The compressed member is often used as a shock absorber on the side of the front wheel 2 of the vehicle. However, the compressed element has a large diameter, which can easily become an obstacle to the layout, in particular when placing a semi-active shock absorber (for example, a damper 9 with damping force control), which includes a damping valve (for example, an actuator 9A) mounted on the side shock absorber, and provided outside the cylinder.

On the other hand, the damper 6, sensitive to the stroke, is installed on the side 2 of the front wheel, which eliminates the restriction imposed on the layout.

[0089] Furthermore, one advantage associated with the flexibility of the design of the stroke-sensitive damper 6 is that since the front wheel 2 side is less likely to be affected by a change in vehicle height due to the number of passengers and weight load than on the side of the rear wheel 3, the side of the front wheel 2 allows you to set the insensitive area and can improve design flexibility, thus leading to, essentially, the implementation of the function of the damper 6, sensitive to the stroke.

[0090] More specifically, the stroke-sensitive damper 6 is configured to change the damping force coefficient at a lower speed, for example, in close proximity to 1 G (acceleration of gravity), to prevent changes in the driving comfort characteristic and the stability of maneuvering from due to differences in the number of passengers and the weight of the load. In particular, the rear wheel 3 is more susceptible to changes in the number of passengers and the load weight than the front wheel 2, which leads to the need to install a wide range where the damping coefficient changes at a lower speed (deadband). Therefore, in the case when the damper 6, sensitive to the stroke, is installed on the side of the rear wheel 3, a sufficient action of its functions requires the provision of a point having a sharp change in speed at which the coefficient of damping force changes, as a result of which an increase in shock (sound and vibrations) with such a sharp change and, thus, design is difficult, which leads to the likelihood that the function of the damper 6, sensitive to the stroke, may be somewhat impaired.

[0091] Therefore, in accordance with the present embodiment, the vehicle can take advantage of the damper 6, which is sensitive to the stroke, and the damper 9 with control of the damping force, to improve control performance, stability of maneuvering and driving comfort while the vehicle is in motion, and improve usability during manufacture and assembly. In addition, the vehicle can use an inexpensive damper 6, sensitive to the stroke on the front wheel 2 side, when an expensive damper 9 with damping force control is used only on the rear wheel 3 side.

[0092] The present embodiment has been described on the basis of the assumption that the state in which the vehicle is controlled is detected using a spring-loaded acceleration sensor 52 and a rotation angle sensor 53 for controlling the damper 9 with controlling the damping force on the rear wheel side 3 using the controller 51 , as an example. However, the present invention is not limited to this, and can be configured to detect the state (conditions) in which the vehicle is moving, using, for example, a vehicle height sensor, a camera in the vehicle, and the like, and outputting such a detection signal to the controller.

[0093] Further, the present embodiment has been described based on the assumption that the stroke sensitive sensor 6 mounted on the front wheel 2 side is implemented using a hydraulic shock absorber including an inner tube 11, an outer tube 12, a piston 15 , piston rod 21, calibration pin 26, return spring 30, first and second channel area adjusting mechanisms 33 and 34, damping force generating mechanisms 35 and 36 on the expansion side and the compression side, and the like, as shown in FIG. . 2, as an example of a stroke-sensitive damper 6. However, the present invention is not limited to this, and it can use not only a shock absorber of a type with two tubes, but also a shock absorber (damper) of a type with one tube on the side with a front wheel, and any arbitrary shock absorber sensitive to the stroke can be used, if only this shock absorber allows to obtain a damping force characteristic such as the characteristic lines 49 and 50 shown in FIG. 4. However, in particular, the use of a stroke-sensitive damper in accordance with the present embodiment allows the damping force on the compression side to be set as a soft characteristic in the range where the piston rod enters the cylinder beyond a predetermined position on the minimum length side , to reduce the stiffness of the roll, and to establish a rigid characteristic when the stroke is then switched to the stroke of the expansion, thereby improving the performance of vibration control in the direction of return.

[0094] The present exemplary embodiment has been described based on the assumption that a mechanical shock absorber with a variable damping force is embodied on the basis of a shock-sensitive shock absorber configured to change the damping force in accordance with the stroke, as an example. However, in the present invention, for example, a frequency sensitive damper configured to mechanically change the damping force may be used.

[0095] Next, the invention will be described, included in the above embodiment. The embodiment described above was described on the basis of the assumption that the shock absorber configured to mechanically change the damping force is embodied as a shock-sensitive shock absorber configured to change the damping force in accordance with the stroke. The shock-sensitive shock-absorber is configured to set a low roll stiffness of the vehicle body on the front wheel side, and the shock absorber with adjustable damping force is configured to vary the roll stiffness of the vehicle body on the rear wheel side using electronic control. Thus, setting a low roll stiffness value on the front wheel side and setting a higher roll stiffness value on the rear wheel side allows you to set the so-called diagonal roll and improve yaw response when the driver drives the vehicle.

[0096] Furthermore, the shock absorber with the adjustable damping force described above is configured to alternately control the damping force on the rear wheel side by means of an actuator such that as the angle of heel of the vehicle body increases, the angle of longitudinal inclination towards the front side the vehicle increases, orienting the vehicle body in a position with the front part lowered, and the shock-sensitive shock absorber described above is made with ozhnostyu provide at this time in the position of the orientation of the vehicle body with a lowered front end on the side of the front wheel. This configuration allows the use of a low-cost shock absorber, sensitive to the stroke, on the front side, thus increasing the longitudinal angle in response to the movement of the roll, leading to diagonal behavior. In addition, this configuration can improve the response of the control operation compared to the vehicle, in accordance with conventional technology, by using a shock absorber with adjustable damping force, which allows to control or configure the roll stiffness control to an appropriate degree using electronic control on the rear wheel side. In addition, this configuration allows us to improve convenience during manufacture and assembly.

[0097] In addition, in accordance with the present embodiment, a stroke-sensitive shock absorber, such as the variable-damping mechanical shock absorber described above, includes a cylinder hermetically containing hydraulic fluid, the piston is tightly mounted to slide into a cylinder and dividing the inner part of the cylinder into two chambers, a piston rod connected to the piston and extending beyond the cylinder, a communication channel configured to establish a message between with two chambers in such a way that the movement of the piston leads to a flow of hydraulic fluid between the two chambers, and a damping force generating device located in the communication channel, and configured to generate a damping force by inhibiting the flow of hydraulic fluid caused by the movement of the piston. The damping force generating device includes a channel area control mechanism configured to control the channel area for the communication channel in accordance with the position of the stroke for the piston rod so as to have at least one of the characteristics of the maximum length side, according to which the damping force on the expansion side is set to a soft state, and the rigid state of the damping force on the compression side is set in the range where the piston rod protrudes from the cylinder outside the specified position of the maximum length side, and the characteristics of the minimum length side, where the damping force of the expansion side is set to rigid, and the damping force of the compression side is set to soft, in the range where the piston rod enters the cylinder beyond the specified position on the side minimum length. Such a configuration can provide, for example, an effect that allows damping to be set for the shock absorber during the roll back to a high value, although the stiffness decreases in the direction of the roll input in response to the control input to obtain a large roll.

[0098] (1) A suspension system that is used in conjunction with a vehicle including a vehicle body, a front wheel and a rear wheel includes a shock absorber with a variable mechanical damping force located between the vehicle body and the front wheel, and configured with the possibility of mechanical changes in the damping force, and a shock absorber with adjustable damping force located between the vehicle body and the rear wheel, and made with the possibility of adjustments damping force using an actuator.

[0099] (2) In the suspension system, in accordance with paragraph (1), a mechanical shock absorber with a variable damping force is a shock-sensitive shock absorber configured to change the damping force in accordance with the stroke. The stroke-sensitive shock absorber is configured to set the vehicle body stiffness low in the roll direction on the front wheel side, and the shock absorber with adjustable damping force alternately sets the vehicle body stiffness on the rear wheel side using electronic control.

[0100] (3) In the suspension system of paragraphs. (1) or (2), the shock absorber with adjustable damping force is configured to vary the damping force on the rear wheel side with the help of an actuator in such a way that, as the angle of heel of the vehicle body increases, the longitudinal angle in the front direction the side of the vehicle increases to orient the vehicle body into a position with the front tilted. The shock absorber with a variable force of mechanical damping is made with the possibility of providing orientation at this time of the vehicle body in a position with lowering the front part on the front wheel side.

[0101] (4) In the suspension system according to any one of paragraphs. (1) - (3), a mechanical shock absorber with a variable damping force includes a cylinder hermetically containing hydraulic fluid, a piston tightly mounted to slide inside the cylinder and dividing the inside of the cylinder into two chambers, a piston rod connected to the piston and extending beyond the cylinder, the communication channel, configured to establish communication between the two chambers so that the movement of the piston leads to the flow of hydraulic fluid between the two chambers, and your generating damping forces located in the communication channel, and configured to generate damping forces by controlling the flow of hydraulic fluid that was caused by the movement of the piston. The damping force generating device includes a channel area control mechanism configured to control the channel area for the communication channel in accordance with the position of the piston rod stroke, so as to obtain at least any of the characteristics on the maximum length side, in according to which the damping force on the expansion side is set to a soft state, and the damping force on the compression side is set to a hard state, in the range where the piston rod protrudes from the cylinder beyond the specified position of the side of the maximum length, and the characteristics of the side of the minimum length, where the damping force of the expansion side is set to a rigid state, and the damping force of the compression side is set to a soft state, in the range where the piston rod enters the cylinder beyond the specified position of the side minimum length.

(5) In the suspension system according to (4),

the damping force generating device includes a pilot type hydraulic damping valve having a pilot chamber. The channel area control mechanism controls the hydraulic pressure in the pilot chamber by adjusting the channel area for the communication channel.

[0102] (6) A vehicle equipped with a shock absorber includes a vehicle body made self-propelled by installing a front wheel and a rear wheel, and a suspension system in accordance with any one of paragraphs. (1) - (5). As one example, a vehicle includes two front wheels and two rear wheels. A mechanical shock absorber with a variable damping force is located between each of the front wheels and the vehicle body. A shock absorber with adjustable damping force, which can adjust the damping force with an actuator, is located on each of the rear wheels and on the vehicle body.

[0103] In accordance with the embodiment described above, both the characteristics of the suspension system and the convenience during manufacturing and assembly can be improved by combining the shock absorber with a variable mechanical damping force configured to mechanically change the damping force and the shock absorber with adjustable damping force. More specifically, a vehicle can take advantage of a shock absorber with a variable mechanical damping force and a shock absorber with an adjustable damping force, thereby improving the performance of the suspension system (e.g. steering performance, maneuvering stability and driving comfort while the vehicle is moving), and also improving convenience during manufacture and assembly.

[0104] Although only some exemplary embodiments of the present invention have been described in detail above, it will be understood by those skilled in the art that many modifications are possible in exemplary embodiments without departing from the new descriptions and advantages of the present invention. Accordingly, all such modifications should be included within the scope of the present invention.

Although embodiments of the present invention have been described above based on some examples, the described embodiments are intended to facilitate an understanding of the present invention and are not intended to limit the present invention. The present invention can be modified and improved, without going beyond its essence, and the invention includes its equivalents. In addition, the elements described in the claims and in the description can be arbitrarily combined or excluded within the range in which the above problems are at least partially resolved, or within the range in which at least part these benefits.

[0105] This application claims priority in accordance with the Paris Convention for Japanese Patent Application No. 2014-156843, filed July 31, 2014.

The entire disclosure of Japanese Patent Application No. 2014-156843, filed July 31, 2014, including the description, claims, drawings and summary of the invention, is hereby presented in its entirety by reference.

The entire disclosure of international publication No. 2013/081004 and the publication of Japanese Patent Application No. 2009-281584, including the description, claims, drawings and summary of the invention, are hereby incorporated by reference in their entirety.

[0106] the List of reference positions

1: vehicle body

2: front wheel

3: rear wheel

4, 7: suspension device

5, 8: spring

6: stroke sensitive damper (shock-sensitive shock absorber, mechanical shock absorber with variable damping force)

9: damping force control damper (shock absorber with adjustable damping force)

9A: actuator

11: inner tube (cylinder)

12: outer tube

15: piston

15A, 15B: oil channel (communication channel)

16: stem side camera

17: bottom side camera

21: piston rod

25: internal stem channel (message channel)

26: measuring pin

30: return spring

33: first channel area adjustment mechanism (damping generation device)

34: second channel area control mechanism (damping force generating mechanism)

35: damping force generating mechanism on the expansion side (damping force generating device)

36: compression side damping force generating device (damping force generating device)

51: controller (control device)

52: spring-loaded acceleration sensor

53: angle sensor.

Claims (45)

1. A vehicle equipped with a shock absorber, comprising: a body of a self-propelled vehicle in which a front wheel and a rear wheel are provided; a mechanical shock absorber with a variable damping force located between the vehicle body and the front wheel and configured to mechanically change the damping force; and a shock absorber with adjustable damping force located between the vehicle body and the rear wheel and configured to control the damping force according to the control signal from the controller using the actuator when turning the vehicle, while the shock absorber with adjustable damping force is configured to change the setting of the rigidity of the vehicle body in the direction of the roll on the side of the rear wheel using electronic control, wherein the shock absorber with adjustable damping force is configured, according to the characteristic, according to which the damping force is set to soft on the expansion side and the damping force is set to hard on the compression side, the damping force is variably controlled on the rear wheel side by means of an actuator so that as the roll angle of the vehicle increases, the angle of longitudinal inclination towards the front of the vehicle increases for orientation Tranfer means to a position inclined front portion, while the mechanical shock absorber with a variable damping force is configured, according to the characteristic, according to which a rigid state of damping force is set on the expansion side, and a soft state of damping force is set on the compression side, to orient the vehicle in a position with the front side tilted on the side front wheel. 2. A vehicle equipped with a shock absorber, comprising: a body of a self-propelled vehicle in which a front wheel and a rear wheel are provided; a mechanical shock absorber with a variable damping force located between the vehicle body and the front wheel and configured to mechanically change the damping force; and a shock absorber with adjustable damping force located between the vehicle body and the rear wheel, and configured to control the force damping force according to the control signal from the controller using the actuator when turning the vehicle, wherein the shock absorber with adjustable damping force is configured, according to the characteristic, according to which the damping force is set to soft on the expansion side and the damping force is set to hard on the compression side, the damping force is variably controlled on the rear wheel side by means of an actuator so that as the roll angle of the vehicle increases, the angle of longitudinal inclination towards the front of the vehicle increases for orientation Tranfer means to a position inclined front portion, while the mechanical shock absorber with a variable damping force is configured, according to the characteristic, according to which a rigid state of damping force is set on the expansion side, and a soft state of damping force is set on the compression side, to orient the vehicle in a position with the front side tilted on the side front wheel. 3. The vehicle according to claim 1 or 2, in which a mechanical shock absorber with a variable damping force includes: a cylinder hermetically containing hydraulic fluid, a piston, tightly mounted with the possibility of sliding, inserted into the cylinder, and dividing the inner part of the cylinder into two chambers, a piston rod connected to the piston and protruding beyond the cylinder, a communication channel, configured to establish communication between these chambers in such a way that the movement of the piston leads to the flow of hydraulic fluid between the two chambers, and damping force generating means located in the communication channel, and configured to generate damping forces by controlling the flow of hydraulic fluid that is caused by the movement of the piston, and wherein the damping force generating means includes a channel area adjustment mechanism configured to adjust the channel area for the communication channel in accordance with the position of the piston rod stroke, so as to obtain at least one of the characteristics on the maximum length side according to which the soft state of the damping force on the expansion side is set, and the hard state of the damping force on the compression side is set, in the range where the piston rod protrudes from the cylinder beyond the specified position on the side with the maximum length, and the characteristics on the minimum length side, where the rigid state of the damping force on the expansion side is set, and the soft state of the damping force on the compression side is set, in the range where the piston rod enters the cylinder beyond the specified Positions on the side of the minimum length. 4. The vehicle of claim 3, wherein the damping force generating means includes a pilot type hydraulic damping valve having a pilot chamber, and wherein the channel area control mechanism controls the hydraulic pressure in the pilot chamber by adjusting the channel area for the communication channel. 5. The vehicle according to claim 1 or 2, in which the vehicle includes two front wheels and two rear wheels with a shock absorber with a variable mechanical damping force located between each of the front wheels and the vehicle body, and a shock absorber with an adjustable damping force located on each of the rear wheels and on the back of the vehicle. 6. A suspension system for a vehicle, including a vehicle body, a front wheel and a rear wheel, the suspension system comprising: a mechanical shock absorber with a variable damping force located between the vehicle body and the front wheel and configured to mechanically change the damping force; and a shock absorber with adjustable damping force located between the vehicle body and the rear wheel and configured to control the damping force according to the control signal from the controller using the actuator when turning the vehicle, while the shock absorber with adjustable damping force is configured to change the setting of the rigidity of the vehicle body in the direction of the roll on the side of the rear wheel using electronic control, wherein the shock absorber with adjustable damping force is configured, according to the characteristic, according to which the damping force is set to soft on the expansion side and the damping force is set to hard on the compression side, the damping force is variably controlled on the rear wheel side by means of an actuator so that as the roll angle of the vehicle increases, the angle of longitudinal inclination towards the front of the vehicle increases for orientation Tranfer means to a position inclined front portion, wherein the mechanical shock absorber with variable damping force is configured, according to the characteristic, according to which a rigid state of damping force is set on the expansion side and a soft state of damping force on the compression side is set, orienting the vehicle in a position with the front part inclined on the front wheel side . 7. The suspension system according to claim 6, in which a mechanical shock absorber with a variable damping force includes: a cylinder hermetically containing hydraulic fluid, a piston tightly mounted with sliding inside the cylinder, and dividing the inside of the cylinder into two chambers, a piston rod connected to the piston and protruding beyond the cylinder, a communication channel, configured to establish communication between the two chambers in such a way that the movement of the piston leads to the flow of hydraulic fluid between the two chambers, and damping force generating means located in the communication channel, and configured to generate damping forces by controlling the flow of hydraulic fluid that is caused by the movement of the piston, and wherein the damping force generating means includes a channel area adjustment mechanism adapted to adjust the channel area for the communication channel in accordance with the position of the piston rod stroke, so as to obtain at least one of the characteristics on the maximum length side according to which the soft state of the damping force on the expansion side is set and the hard state of the damping force on the compression side is set in the range where the piston rod protrudes from the cylinder beyond the specified position on the maximum length side, and the characteristics on the minimum length side, where the rigid state of the damping force on the expansion side is set, and the rigid state of the damping force on the compression side is set, in the range where the piston rod enters the cylinder beyond the specified position on the side of the minimum length. 8. The suspension system of claim 7, wherein the damping force generating means includes a pilot-type hydraulic damping valve having a pilot chamber, and wherein the channel area control mechanism controls the hydraulic pressure in the pilot chamber by adjusting the channel area for the communication channel. 9. The suspension system of claim 6, wherein the vehicle includes two front wheels and two rear wheels, wherein a mechanical shock absorber with a variable damping force is located between each of the front wheels and a vehicle body, and a shock absorber with an adjustable damping force is located on each of the rear wheels and on the back of the vehicle. 10. A vehicle equipped with a shock absorber, comprising: a body of a self-propelled vehicle in which a front wheel and a rear wheel are provided; a mechanical shock absorber with a variable damping force located between the vehicle body and the front wheel and configured to mechanically change the damping force and comprising a cylinder and a piston rod axially displaceable from a maximum length to a minimum length, a shock absorber with adjustable damping force located between the vehicle body and the rear wheel and configured to control the damping force with an actuator, the mechanical shock absorber with a variable damping force has a characteristic that allows you to change the damping force to a soft state when the position of the piston rod relative to the cylinder is in the range in which the piston rod enters the cylinder beyond the specified position on the minimum length side, and then change the damping force to a hard state when the stroke is switched to the expansion stroke. 11. The vehicle of claim 10, in which the shock absorber with adjustable damping force is configured to control the damping force according to the control signal from the controller, however, the controller is configured to set a higher roll stiffness value by means of a shock absorber with adjustable damping force so that the longitudinal angle in the direction of the front side of the vehicle increases to orient the vehicle in the position with the front part tilted with increasing roll angle of the vehicle. 12. The vehicle of claim 10 or 11, in which the mechanical shock absorber with a variable damping force is a shock-sensitive shock absorber configured to change the damping force in accordance with the stroke.

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